1. Field of the Invention
The present invention pertains to a controller for an electrical resistance heater, and more particularly, pertains to an integral sensor controller for an electrical resistance heater where the electrical resistance heater exhibits a positive temperature coefficient of resistivity, which provides for control of the electrical heater by using the resistance versus temperature characteristic of the heater.
2. Description of the Prior Art
Representative prior art patents include U.S. Pat. Nos. 3,675,046 and 3,700,933, for heater control circuits where a load is pulsed with energy to monitor the condition of the load. U.S. Pat. No. 3,758,844 provides a heater control circuit which also provides for zero switching and overload protection.